Sports such as baseball often require repeated violent overhead arm motion which can lead to injury. The science of baseball pitching has been highly refined to reduce the chance of catastrophic injury. Sports therapists can identify the proper arm motion during a pitch which exposes the arm tendons and muscles to the least amount of stress. Quite understandably, it is not usual for the average young pitcher to receive intensive pitching instruction directed specifically toward preventing injury. Young boys have small hands so they hold a baseball with finger "under" the ball. A pitching motion starting this way can lead to injury. If a young pitcher continues throwing in this manner it becomes "muscle memory" and is extremely hard to correct. It is worse to practice something wrong than to not practice at all. The arm held alarm device of the present invention if used correctly over 4 to 6 weeks will develop "muscle memory" that can greatly reduce arm injury. "Muscle memory" using good mechanics is the goal of this invention. More likely, young pitchers learn from their fathers or little league baseball coach who may not properly emphasize the danger in using, or give repeated lessons to correct, improper technique. Furthermore, although injury normally happens as a result of chronic overuse, major arm injury has been known to occur after only a small number of pitches with the wrong technique, thus making beginning lessons even more critical. There have been numerous attempts to develop automated devices to help condition people to perform a particular activity in the correct manner. In particular, a number of devices to help bowlers learn the correct delivery and follow through are known. One such device is shown in U.S. Pat. No. 4,330,123 issued to Kleinerman wherein a device resembling a wrist watch is worn by the bowler. In one mode, the device includes an acceleration-activated switch and a gravity-activated switch which must be tripped in sequence upon a specified correct bowling motion for an annunciator to sound. In an alternative mode, the device houses two mercury switches connected to a circuit having a plurality of logic elements. Depending on the orientation of the wrist of the bowler, and disposition of the mercury switches, an annunciator is activated by one of two timers. The device is designed to signal the bowler when a correct backswing and follow-through have been achieved. Despite attempts to provide training devices for bowling and other activities, there is an need for an improved training device for teaching baseball pitchers the proper throwing motion to help avert career-disabling injury.